Quick Tips : How to Zone Focus / Scale Focus

There’s always something new to learn in photography. Even people who’ve been shooting for years have little gaps of knowledge intermittently speckled throughout their skill set. This in mind, we’re starting a new feature that will quickly and directly answer some of the more common questions that puzzle shooters, both new and old. In coming articles, we’ll explain things like ISO, crop-sensors, and the intricacies of home-printing. For now, let’s look at zone focusing (sometimes known as scale focusing), how it’s done, and how it can help your photography.

Zone focusing is a technique used to quickly and accurately achieve proper focus on a subject in photography when it’s not practicable to compose a shot through the viewfinder. By setting a lens’ aperture and focus rings to a set position, it’s possible to shoot in-focus photos candidly, quickly, and accurately in situations where autofocus (AF) lag or contemplative composition would otherwise cause you to miss the shot. Simply observing the numbers and position of the focus scale (sometimes called depth-of-field scale) will let you know what will be in focus before you take the shot.

The focus scale of an old, Petri rangefinder.

It can sound complicated, but it’s not, as long as you understand depth-of-field and how this is affected by the photographer. If you’re unfamiliar with the concept of depth-of-field, the basics are that by setting the aperture of a camera lens to different values (ƒ/1.4, 5.6, 8, etc.) the photographer can change how much of the photo will be in focus. This concept is known as “depth-of-field”, and understanding it is crucial to creative photography. Larger apertures (lower numbers) yield very shallow depth of field, creating images that isolate the subject in focus while blurring the background and foreground into pleasant bokeh. Smaller apertures (higher numbers) create images in which more of the composition is in focus, perfect for landscapes and photojournalism.

Zone focusing uses the photographer’s understanding of depth-of-field to allow the shooter to know what parts of the photograph will be in focus by simply looking at the camera lens. Most manual focus lenses have a distance scale on their focusing ring to indicate which areas of a composition will be in focus based on the set aperture. By looking at the focus ring in relation to the focus scale, it’s possible to see that when set to ƒ/8, for example, everything that falls between the markers for “8” will be in focus. As you spin the focus ring, the distance scale rotates to show that the area in focus is changing.

Let’s illustrate the point. In the photo here, we can see the lens aperture has been set to ƒ/4. Looking at the depth-of-field scale and focusing ring we can see that when set to ƒ/4, everything that’s between 3.5 and 5 feet away will be in focus. If we then change the aperture to ƒ/22 we can see that even without moving the focus ring the depth-of-field changes to bring everything from infinity to 2 feet away into focus.

Using this technique, the shooter sets the aperture and then simply makes sure the subject is within the marked distances when taking the shot. This allows for rapid and candid shooting, crucial in street photography, or when fast moving subjects negate the possibility of viewfinder composition.

This shot was taken using zone focusing. By setting the scale and running alongside my dog, focus was fairly easy to achieve.

The technique is most valuable to photographers using older cameras and manual focus lenses, but shooters using modern machines can also benefit from this knowledge. Leica has always seemed to understand the value of the focus scale, and newer lenses from Fujifilm, Olympus, and others have recently included them as more manufacturers embrace the tactile functionality of days past.

So that’s it. Try it out and let us know how it goes. If there’s something in photography that you’ve just not been able to wrap your head around, or just a niggling little technique that you haven’t had time to read up on, write about it in the comments and maybe it will get featured.

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[…] our recurring feature explaining in simple terms certain key elements of photography, is back. Last time we took a look at the focus scale, how to zone focus, and when to use the technique. Today we’ll talk about one of the most basic […]